Well the only way EB wins in the threat department is if in fact you find yourself forced to Hammer Shot more often with Gut, because otherwise Gut seems to convincingly do more damage. Albeit the threat curve is different (upfront vs. over time.) I suspect Bioware wants us to use EB, so if Gut does "win" I wouldn't be surprised to see EB buffed (win/win.)
Regarding simplicity, I have two points:
1 - Simple is actually better when tanking; having highly involved rotations sounds "cool" in theory but in practice is only compelling when you're bored out of your mind bashing some random tank-and-spank boss. With dynamic encounters, adding excessive (key word) complexity to rotations often adds a layer that just becomes frustrating.
2 - I'm not sure Gut makes life materially easier as now you have to manage another debuff while playing with UI: Circa 1998™. I do think EB will be more fun to "theorycraft" but I don't think Gut changes things so much that you can just bash a key while watching TV.
Definitely enjoying the dialogue and I'm more than happy to be proven wrong in the long-run regarding Gut. Maybe it's the fact I played a Druid tank/healer in WoW that makes me miss those lovely bleeds!